Aircraft cabin pressure control means



y 1948. w. D. TEAGUE, JR 2,441,089

AIRCRAFT CABIN PRESSURE CONTROL MEANS I Filed May 16, 1944 2Sheets-Sheep l IN V EN TOR.

ATTURNEY May 4, 1948. w. D. TEAGUE, JR 2,441,089

AIRCRAFT CABIN PRESSURE CONTROL MEANS Filed May 16, 1944 2 Sheets-Sheet2 WalberD.

ATTORNEY Patented May 4, 1948 units!) sr airless t-roaar'r' oABrNranss'oan contract.

. mans Walter ill). 'ileague, in, Alpine, N. 3., asslgnor to Bendix;Aviation Corporation,

Teterboro, N. ll,

a corporation of Delaware Application May it, 1944, Serial No. 535,887

6 Clas.

This invention relates to novel and improved control means, methodsand-systems for maintaining air at suitable predetermined pressures in aclosed or sealed compartment of an aircraft and more particularly toimprovements in an air inlet and outlet control mechanism and valve andinmethods and systems for regulating the pressure within an aircraftcabin of a type such as shown, for example, in the U. S. Patent No.2,002,057 to Green. dated May 21, 1935. The present application is acontinuation in part of my copending application Serial No. 524,063,filed February 26, 19%.

An object of my present invention is to provide novel means forregulating the air pressure within an aircraft cabin so as to preventsuch cabin pressure from dropping below a predetermined pressure valuerelative to atmospheric pressure.

Another object of my invention is to provide a novel system and meansfor maintaining aircraft cabin pressure between predetermined minimumand maximum values relative to atmospheric pressure.

Another object of my invention is to provide a novel system and meansfor increasing aircraft cabin pressure to a predetermined maximum valueabove atmospheric pressure and so controlling such pressure duringaircraft maneuvers as to prevent such cabin pressure from decreasingbelow a predetermined minimum value relative to atmospheric pressure.

Another object of, my invention is to provide novel means wherebyaircraft cabin pressure may be limited to a maximum difierential aboveatmospheric pressure and also to prevent cabin pressure from droppingsubstantially below at= mospheric pressure regardless of the maneuversof the aircraft.

Another object of my invention is to provide a novel method and systemfor supercharging an aircraft cabin and limiting such superchargedpressure to a maximum diiierential above at mospheric pressure, andpreventing such cabin pressure from decreasing below a safepredetermined value relative to the atmospheric pressure at the flightlevel of the aircraft.

Another object of my invention is to provide in a single housing apressure relief valve, to-

gether with a vacuum relief valve for regulating the value of thepressurewithin an aircraft cabin relative to the atmospheric pressure atthe level of flight of the aircraft.

The above and furtherobjects and novel features of this invention willmore fully appear from the following detailed description and theaccompanying drawings wherein like reference characters refer to likeparts in the several views. It is to be expressly understood, however,that the drawings are for the purposes or illustration only and are notdesigned as a definition of the limits of the invention, reference beingbad vfor this purpose to the appended claims. i

In the drawings.

Figure l is a schematic view illustrating my novel system and method forpressurizing an aircraft cabin and showing a somewhat enlarged explodedside view or" the cabin pressure con trol mechanism.

Figure 2 is an enlarged sectional view of the cabin pressure controlmechanism of Figure l illustrating the operating parts thereof.

Referring to the drawings it will be seen that, as shown schematicallyat Figure i, there is pro vided a supercharger or other air pressuresource indicated by the numeral l which may be driven by an aircraftengine 2 or other suitable power means.

The supercharger i has provided an air inlet conduit indicated by thenumeral 3 and a discharge conduit 6 leading to the interior or anaircraft cabin The conduit 13 thus supplies air under pressure to thecabin 5 at a pressure greater than atmospheric pressure. I have furtherpro= vided a control valve mechanism indicated generally by the numeral6 arranged to control a suitable opening through the floor or wall ofthe cabin so as to normally maintain the pressure of the air withinthecabin 5 within a predetermined pressure range relative to thepressure of the atmosphere. The control valve mechanism 6, as will beexplained hereinafter, isso arranged as to open the cabin to atmosphericpressure upon the value of the cabin pressure rising to a pressure inexcess of a predetermined differential above atmospheric pressure so asto thereby'decrease the cabin pressure to a safe value. More= over, thecontrol valve 6 is also arranged to open the cabin to atmosphericpressure upon the relative values of cabin and atmospheric pressurechanging so that the atmospheric pressure exceeds the pressure withinthe cabin t by a predetermined value as may occur during diving or otherlike maneuvers of the plane and thus prevents relative cabin andatmospheric pressures exceeding predetermined safe values.

As best shown in Figures 1 and 2, the control valve mechanism includes amounting plate 5 which may be affixed to a wall or floor 8 of theaircraft cabin 6 by bolts 9. The plate I has formed thereon an annularflange Hi arranged to fit within a suitable opening in the iioor 8 ofthe cabin. A nozzle ii projects concentrically from the plate 8,outwardly from the interior of the cabin ii. The nozzle it has an innercurved surface which is fiared at theopposite ends thereof so as todefine a nozzle passage It. An annular opening i 3 is formed in theplate 1 and surrounds the nozzle It in concentric relation therewith.

Extending across the opening i3 is a rib indicated by the numeral Mformed integral with the plate 1, nozzle H and flange l3 whereby thenozzle H is supported in concentric relation to the annular opening l3.Secured to the rib l4 by a screw I5 is a collar I5. which surrounds theouter edge of the nozzle ll. Formed integral with collar l5 are arms Hwhich project radi ally from a sleeve |3 positioned concentrically inthe nozzle passage H for supporting a tubular member I!) extendinglongitudinally in the passage l2, as will be explained hereinafter.

Mounted at the inner side of the plate 1 is a cylindrical member 23supported on the plate I by suitable leg members 2| positioned in spacedrelation and projecting from an annular plate member 22 fastened to theplate I by bolts 25. As shown in Figure 2, the cylindrical member 23 hasformed therein a wall 24 separating the cylinder 23 into two chambers 25and 25.

The tubular member I! supported by the arms i1 extends longitudinally inthe passage |2 through the wall 24 into the chamber 25. The

' tubular member l3 has provided a shoulder portion 21 which is seatedin a recess 23 provided in the wall 24 so as to prevent outwardlongitudinal movement of the tubular member I3. A pin 23 is fixed in thetubular member I! so as to engage the outer edge of the sleeve l3 forpreventing inward longitudinal movement of the tubular member 13.

The tubular member l3 forms a central guide on which rides a bearingsleeve 33. The bearing sleeve 33 has formed integral therewith a plate3| to which is afilxed a cylindrical gate valve 32 forming a pistonlongitudinally movable in the cylindrical chamber 25 and slightly spacedfrom the parallel inner surface of the cylindrical chamber 23 so as topermit a limited leakage of cabin air into the chamber 25 so as to forma pneumatic motor means for adjusting the gate valve 32, as will beexplained hereinafter. The cylindrical gate valve 32 is longitudinallymovable in relation to the passage l2 and has provided at one end anannular knifelike edge 33 adapted to engage at an acute angle the innersurface of the passage |2.

Mounted within the cylindrical gate valve 32 at the opposite side of theplate 3| from the chamber 25 is a sleeve member 34 having'an open endspaced apart from the plate 3| and an opposite end closed by a conicalshaped'baflle plate 35 which projects longitudinally into the passage l2and in spaced relation to the inner surface thereof. A sleeve member 35is positioned concentric with and at the apex of the conical shapedbaflle 35. Extending through the sleeve 35 is the tubular member |3which is am ed to the battle plate 35 by a suitable fastening pin 31.The cylindrical gate valve 32 slides alon the sleeve member 34 definingwith the inner surfaces of the bafile plate 35, sleeve 34 and plate 3| achamber indicated by the numeral 33. A slot 33 opens through the wall ofthe cylindrical gate valve 32 at a point above the open end of thesleeve member 34 so as to open into the chamber 35. Thus the chamber 33is open to cabin pressure, as will be explained hereinafter.

A light spring indicated by the numeral 43 bears at one end upon thewall 24 and at its opposite end upon the plate 3| of the sleeve valve 32so as to normally hold thejmiIe-llke edge 33 of the sleeve valve 32 incontacting relation to the inner surface of the passage l2 so as toprevent cabin air from flowing to atmosphere.

As best indicated in Figure 2, the inner surface of the passage i2 isdesigned for the full rated maximum flow of air, with the conical shapedbaille member 35 sufficiently spaced from the nozzle proper for suchflow and with the area normal to the stream progressively decreasing soas to smoothly accelerate the air flow from the cabin into the nozzlepassage l2. The sleeve valve 32 as shown contacts the nozzle surface l2.as shown in Figure 2, so as to close the valve.

The cylindrical member 23, as previously described, has provided the legmembers 2| which are positioned in spaced relation so that the slot 33in the sleeve valve 32 and the inner flared end of the nozzle passage I2is at all times open to cabin pressure.

The chamber 25 communicates with cabin pressure through leakage aroundthe sleeve valve 32, and with the chamber 25 through a bleed valveopening 4| having a ball valve 42 normally biased to a closed positionby a spring 43. The spring 43 is held in operating relation by a screwmember 44 engaging suitable screw threads formed in a tubular member 45mounted in the wall 24. The tubularmember 45 is arranged to support theball valve 42 and spring assembly 43, and has provided a slot 45 wherebyupon opening of the bleed valve 42 air may freely flow from the chamber25 to the upper chamber 25. The chamber 25 has suspended therein abellows 41 afilxed to a plate member 45, as shown in Figure 2. The plate43 extends across the top of the chamber 25 and is held in positionbetween a top plate 43 and the open end of the cylinder 23 by screws 53.A suitable orifice 5| is formed in the top plate 43 so as to open theinterior of the bellows 41 to cabin pressure.

A tubular member 52 projects longitudinally from the top plate 43 intothe interior of the bellows 41 and has an end 53 opening into theinterior of the bellows 41 and serving as a stop for limiting movementof bottom plate 54 of bellows 41, as will be explained.

The tubular member I3 is open at its outer end 55 to atmosphericpressure and at its opposite end 55 opens into the chamber 25 so thatatmospheric pressure acts upon the bottom 54 of the bellows 41.

The bellows 41 rests in a cup-like member 51 held by one end of ahelical spring 58 which biases the bottom plate 54 of the bellows 41against the open end 53 of the tubular member 52. The helical spring 53is supported at its opposite end by the wall 24.

A lever 53 is pivotally connected at 53 to a projecting member 5| whichis afllxed to wall 24, as shown in Figure 2. The lever 53 has aprojecting pin 52 which bears upon the ball valve 42. The ball valve 42is normally biased to a closed position by the spring 43 previouslydescribed. An adjustable set screw indicated by the numeral 53 isprovided in the bottom plate 54 of the bellows 41. The set screw 53 isarranged to operate the lever 53 so that upon expansion and contractionof the bellows 42 the lever;tends to open and close the bleed valve 4|.The set screw 63 has provided a suitable cleft portion 54 whereby thescrew'53 may be manually adjusted for calibration purposes by a screwdriver or other suitable tool inserted through the orifice 5| andengaging in the cleft portion 54.

Thus upon a difference in atmospheric and cabin pressure less than apredetermined maximum value, the bellows will be biased by atmosphericpressure against the tubular stop 53. Therefore, the bleed valve 4| willbe closed under the biasing force of the spring 51, and the pres sure inthe chamber above the plate 3i will be substantially that of the'cablnpressure, since its only outside conduit is to the cabin in the form ofthe leakage past the outer surface oi the gate valve 32 and the innersurface of the cylindrical chamber 25. Thus since the plate 3| of thevalve 32 willbe subject to cabin pressure in the chamber 25, the spring40 will tend to hold the sleeve valve 32 in a closed position. However,as the difference between cabin and atmospheric pres= sures increase toa value in excess of a predetermined maximum value, the bellows 41 underthe biasing force of the cabin pressure supplied through the tubularmember 52 will cause plate 54 to move away from the end 53 of thetubular member 52, causing the bellows 4! to actuate the arm 59 so as toopen the bleed valve ii.

The position of the set screw 63 may be readily adjusted to determinethis opening value. The opening of the bleed valve 4i communicateschamber 25 to atmospheric pressure through slot 46, the tubular member45, bleed valve 45, and tubular member IS. The biasing force of thecabin pressure in chamber 38 acting upon plate 3|, counteracts thebiasing force of the spring 40 and atmospheric pressure in chamber 25,causing the gate'valve 32 to open passage so as to allow air to escapefrom the cabin and thereby prevent further increase in the difierencebe-= tween cabin and atmospheric pressure. Thus the piston formed by thesleeve 30, plate 39 and cylindrical gate valve 32 provides a motor meansfor adjusting the gate valve 32.

i As shown in Figure 2,. there is further provided a casing member 65which is supported by' a shoulder 56 provided on the cylindrical mem ber20. The casing 65 has further provided an annular flange 6i fastened inspaced relation to the plate 1 by screws 68. The screws 68 have formedsuitable sleeve-like spacing members 69, i0 and H which support inspaced relation the annular flange 61 and 13.

ill to a bracket 82 fastened to the casing t5, at the inner side thereofby a suitable bolt or rivet 83. The link member 83 is pivotallyconnected at iii to a bracket member 82A fastened to the ring valve 74by suitable rivets or bolts 83A. The link members i9 and B0 are in turnpivotally connected at 84 forming a joint at which point there is'provided a spring element 35 which tends to bias the link members I9 and80 into an extended position, as shown in Figure 2, so as to hold thering valve 14 on its seat in the absence of a suflicient pressuredifferential between the cabin and atmospheric pressures. The fourtoggle joints 18 are so arranged as to allow the ring valve member 14 tomove up and down in a straight line but not to permit sideward movementor tipping. The springs 85 are further provided of such strength that ifthe atmospheric pressure increases above cabin pressureto a pre Theannular opening i3 in the plate 5, previwill be increased to approachatmospheric pressure. The diii'erentiai of cabin pressure aboveatmospheric pressure. however, serves to force the ring valve member I!more firmly on its seat so as to decrease possible leakage.

As shown in Figure 1, there isprovided the supercharger i driven by theaircraftengine or any other suitable power means whereby the pressurewithin the cabin indicated by numeral 5 may be increased aboveatmospheric pressure so as to avoid harmful physiological effects uponthe passengers or crew of the aircraft due to pressure at highaltitudes.

The valve indicated generally by the numeral 3, in the illustration 01Figure 1, as previously described, will maintain pressure within thecabin and at a predetermined difierential above atmospheric pressure.Moreover, upon maneuvering the plane so as to dive rapidly, for example,from a high altitude to a low altitude. the atmospheric pressure will inmany cases increase so rapidly as to exceed the pressure within thecabin causing in extreme cases the collapse of the cabin. The ring orplate valve member 74 in my invention, however, will be forced. open bythe difference between the cabin and atmospheric pressures to permit theequalization of pressure within the cabin to that of atmosphericpressure so as to prevent such unequal stresses from being applied tothe cabin walls.

Thus it will be seen that through my invention predetermined upper andlower limits oi the cabin pressure in relation to atmospheric pressuremay be readily provided.

Although only one embodiment of the invention 'has been illustrated anddescribed, various Gib ring-like members We and v chamber,

determined value of, for example, .10 of an inch Hg above cabin pressurethe ring valve will be forced wide open, whereupon the cabin pressurechanges in the form and relative arrangement of the parts, which willnow appear to those skilled in the art, may be made without departingfrom the scope of the invention. Reference is, therefore, to be had tothe appended claims for a deft nition of the, limits of the invention.

What is claimed is:

i. A mechanism for within a supercharged aircraft cabin. comprising, incombination, a mounting plate for supporting such mechanism in anopeningin the wall of said aircraft cabin, said mounting plate havingformed therein a valve opening, a tubular member projecting through saidvalve opening, a piston valve longitudinally movable on said tubularmember for opening and closing said valve opening, a housing havingformed therein a cylindrical chamber open at one end thereof, saidpiston valve longitudinally movable in said cylindrical spring tensionmeans biasing said piston valve outwardly through the open end of saidcylindrical chamber, said piston valve subiect to cabin pressure atopposite sides thereof, said housing having formed therein a secondchamber, valve means for bleeding cabin pressure from said cylindricalchamber into said second chamber, said tubular member opening saidsecondchamber to atmosphere, whereby the cabin pressure applied at oneside of said piston valve may be diminished so that the piston valve maybe biased under force of cabin pressure at the opposite side into saidcylindrical chamber so as to cause said piston valve to open said firstvalve opening, and means responsive to changes in atmospheric and cabinpressures for controlling the opening of said valve means.

2. A mechanism for controlling the pressure within asuperchargedaircrait cabin, comprising. in combination, a mounting platefor supporting controlling the pressure asap such mechanism in anopening in the wall of said aircraft cabin, said mounting plate havingformed therein a first valve opening, a second valve opening, a tubularmember projecting through said first valve opening, a piston valvelongitudinally movable on said tubular member for opening and closingsaid first valve opening, a housing having formed therein a cylindricalchamber open at one end thereof, said piston valve longitudinallymovable in said cylindrical chamber, spring tension means biasing saidpiston valve outwardly through said open end, said piston valve subjectto cabin pressure at opposite sides thereof, said housing having formedtherein a second chamber, valve means for bleeding cabin pressure fromsaid cylindrical chamber into said second chamber, said tubular memberopening said second chamber to atmosphere, whereby the cabin pressureapplied at one side of said piston valve may be diminished so that thepiston valve may be biased under force of cabin pressure at the oppositeside into said cylindrical chamber so as to cause said piston valve toopen said first valve opening, and means'responsive to changes inatmospheric and cabin pressures for controlling the opening of saidvalve means, a plate valve controlling said second valve opening, springtoggle operating means for biasing said plate valve so as to close thesecond valve opening, and said plate valve arranged to open the secondvalve opening upon the atmospheric pressure exceeding the cabin pressureby a predetermined value.

3. A mechanism for controlling the pressures within a superchargedaircraft cabin, comprising,

in combination, a piston valve for regulating a valve opening, a housinghaving a first chamber formed therein and open at one end thereof, saidpiston valve longitudinally movable in said first chamber for openingand closing said valve opening, spring means biasing said piston valveoutwardly through the open end of said first chamber in a valve closingdirection, said piston valve subject to cabin pressure at opposite sidesthereof, said housing having a second chamber formed therein, a bellowsmounted in said second chamber, the interior of said bellows open tocabin pressure, a tubular member projecting through said valve openingand slidably supporting said valve member, said tubular member openingthe second chamber to atmospheric pressure so as to cause atmosphericpressure to be applied to the exterior surface of said bellows, valvemeans to bleed cabin pressure from said first chamber and at one side ofsaid piston to the second chamber, and said valve means operativelycontrolled by said bellows so as to regulate said piston valve.

4. A mechanism for controlling the pressure within a superchargedaircraft cabin, comprising, in combination, a mounting plate having afirst valve opening and a second valve opening extending about the firstvalve opening, a first valve member for controlling the first valveopening, motor means for positioning the first valve member, meansresponsive to said cabin pressure for .controlling the motor means, anannular plate for controlling the second valve opening, and spring meansbiasing said annular plate in a direction for closing said second valveopening against atmospheric pressure, and said annular plate biased to avalve opening position upon the atmospheric pressure exceeding the cabinpressure by a predetermined value.

5. A mechanism for controllin the pressure within a superchargedaircraft cabin, comprising." in combination, a mounting plate (orsupporting such mechanism in an opening in the wall of said aircraftcabin, said mountin plate having formed therein a first valve openingand a second valve opening extending about the first valve opening, afirst valve member for opening and closing said first valve opening,first spring means carried by said plate for biasing the first valvemember to a closed position against cabin pressure, said first valvemember arranged so as to open under excessive cabin pressure, a secondvalve member in the form of an annular plate for opening and closingsaid second valve opening. a second spring means carried by said platefor biasing the second valve member to a closed position againstatmospheric pressure, and said second valve member being so arranged asto be diilerentiali-y eflected by cabin and atmospheric pressures so asto open said second valve opening upon atmospheric pressure exceedingthe cabin pressure by apredetermined value. 7

6. A mechanism {or control of aircraft cabin pressure, comprising incombination, valve means including a valve opening, a tubular memberprojecting through said valve opening, a valve member longitudinallymovable on said tubular member and mounted for movement relative to thetubular member for regulating said-valve opening, a cylinder element, apiston element for operating said valve member and slidably mounted insaid cylinder element, at least one of said elements providing a passageto permit a fluid leakage to oneside of the piston element from theother side thereof, said piston element subject at said other side tocabin pressure, a second valve located in the wall of said cylinderelement at the one side of said piston element and arranged to bleed theleakage fluid from the one side of said piston element and to theatmosphere through said tubular member so as to effect movement of saidvalve member under cabin pressure in a valve opening direction. a springbiasing said valve member in a valve closing direction, a fiuid pressureresponsive membrane for controlling the opening of said second valve soas to regulate the operation of said valve member, one side or saidmembrane subject to cabin pressure and the opposite side of saidmembrane subject to atmospheric pressure applied through said tubularmember.

WALTER. D. TEAGUE, Ja.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

